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Orbital Sciences to develop space station cargo ship

By David Shiga

Orbital Science’s Cygnus spacecraft could carry 2.3 tonnes of cargo to the space station on each flight (Illustration: Orbital Sciences)

NASA will pay the aerospace firm Orbital Sciences up to &dollar;170 million to help the company develop a rocket and spacecraft that could carry cargo to the International Space Station (ISS). Funds were freed for the deal after NASA severed its relationship with another commercial partner that had failed to meet fundraising goals.

With the space shuttle set to retire in 2010, NASA is looking for alternative ways to transport astronauts and supplies to the space station. NASA’s own shuttle replacement – the Orion spacecraft and Ares I rocket – is not expected to be ready until at least 2015.

In 2006, NASA signed agreements earmarking &dollar;485 million to be split between two companies trying to develop vehicles to service the orbital outpost. As part of its Commercial Orbital Transportation Services (COTS) programme, it set aside &dollar;278 million for SpaceX, based in El Segundo, California, and &dollar;207 million for Rocketplane Kistler of Oklahoma City, both in the US.

The money was to be gradually doled out between 2006 and 2010 – as long as the two companies kept meeting performance milestones along the way. But after Rocketplane Kistler failed to raise a required &dollar;500 million in private financing, NASA cancelled its agreement with the company in October 2007 and called for proposals from other companies interested in a COTS partnership.

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Now, NASA has selected Orbital Sciences, based in Dulles, Virginia, US. The company developed NASA’s Dawn spacecraft, which successfully launched in 2007 on its way to visiting the asteroids Vesta and Ceres. Orbital also built the ill-fated DART spacecraft, a failed demonstration of automated satellite rendezvous and docking technology.

Medium-lift rocket

Orbital plans to develop a spacecraft called Cygnus and a new medium-lift rocket called Taurus II to hurl it into orbit. Cygnus will be designed to carry 2300 kilograms of cargo to the space station and return up to 1200 kilograms of cargo to Earth. The company plans to make a demonstration flight to dock with the space station in December 2010, launching from NASA’s Wallops Flight Facility in Virginia, US.

The spacecraft is designed to sidle up close enough for the space station’s robotic arm to grab it and bring it in to dock. The company says it could make as many as eight Cygnus flights per year to the space station.

The decision marks “another exciting day for us at NASA”, says Doug Cooke, deputy associate administrator for the exploration systems mission directorate at NASA headquarters in Washington, DC, US. “I think it’s a testament to NASA’s commitment to stimulating the commercial space market and the capability we’re hoping to enjoy in the future.”

Satellite launches

Orbital’s proposal beat out 12 others that NASA had considered for COTS funding. It was the best proposal based on both technical feasibility and financial viability, NASA officials said.

Orbital has earmarked &dollar;150 million of its own money to develop the rocket and spacecraft. The company believes its Taurus II rocket could be used not only for space station cargo missions, but also to launch robotic probes to other planets, commercial satellites and space missions for the US defence department.

The agreement with NASA does not include a plan to transport human crews to the station, but NASA says it has discussed that possibility with the company. “They did not formally propose that as part of this, but they certainly have concepts that could be used in the future,” said Alan Lindenmoyer, manager of NASA’s Commercial Crew and Cargo programme at the Johnson Space Center in Houston, Texas, US, in a conference call with reporters.